Ice making equipment of the general type described is exemplified by U.S. Pat. No. 3,288,202. This equipment however has certain shortcomings. First, heat transmission between the freezing chamber and the refrigeration coil is not optimized. As a result the amount of ice produced per hour is not as great as it could be. Second, the ice layer built up on the inside of the ice forming chamber is not always uniform in thickness. Consequently, the ice pieces which are formed from it are not uniform in size and as a result the qualities of the finished product cannot be controlled as closely as desired. Third, in prior equipment of the type in which ice is stored in a hopper above the ice forming chamber, the ice is not always reliably dispensed from the hopper in uniform quantities. In prior equipment the ice is typically dispensed by means of an agitator that includes one or more arms which project radially from a central drive shaft aligned with the vertical axis of the hopper. Ice pieces in the hopper will sometimes stick together or freeze to the wall of the hopper. Such a condition can overload the motor and in some cases damage parts or even stall the motor causing the equipment to malfunction, entirely preventing ice from being dispensed. Another problem is the lack of uniformity in the volume of ice dispensed. In some prior equipment this may be in part due to the fact that the volume of ice near the dispenser outlet changes from time to time so that when the agitator is operated, there is no reliable way to tell how much ice will actually be dispensed from the hopper.
In view of these and other deficiencies of the prior art it is a general objective of the invention to provide an improved apparatus for efficiently producing clear transparent cracked ice at a relatively high capacity in terms of pounds per hour compared with prior equipment of substantially the same overall size. It is another objective to reduce the tendency for the ice dispensing agitator or conveyor from becoming overloaded or stalled and to assure that uniform quantities of ice will be dispensed during each cycle of its operation. It is another object to help assure that the ice sheet formed within the refrigeration chamber is uniform in size, distribution and thickness thereby making sure that the ice delivered to the storage hopper will be uniform with less tendancy to pack or become frozen in place and thereby assuring efficient operation of the dispensing conveyor. Yet another object is to maximize heat transfer between the refrigeration coil and the refrigeration chamber to assist the ice forming means in producing an ice layer of uniform thickness while at the same time enabling the refrigeration chamber to be made of two tubular wall members each formed from a simple sheet metal tube of uniform wall thickness.
These and other more detailed and specific objects of the invention will be apparent in view of the accompanying specification and drawings which illustrate the invention by way of example.